1. Field of the Invention
The invention concerns a heating device, a method for the production of a heating device, a heatable object and a production method for such an object.
2. Prior Art
In numerous operational areas, electrical heating means are used to bring objects to desired temperatures. As a result of their good adjustability and simple design, resistance heating is preferred. The use not only of conductive materials but also, among others, electrically conductive plastic for this purpose is known. This opens up an additional broad design area for corresponding heating devices, particularly when contrasted with the limitations of ordinary metal conductive materials.
From DT 26 16 771 A1, a composite heating panel, made of a plastic laminate, with an incorporated semiconducting layer is known, which provides directed radiant heat. This laminate consists of a rigid plastic laminated structure, which is formed from at least one layer of a reinforced substrate basic material and a resin coating on this material, a semiconductive carbonaceous pyropolymer, which is bound to a heat-resistant, inorganic oxide support of large surface area, which is incorporated on at least one side of at least one layer of the substrate material, a heat-reflecting layer, incorporated in a position on one side of the pyropolymer on the substrate material, and power supply devices to parts of the layer made of conductive, carbonaceous pyropolymer, and which produces electrical resistance heating in the laminate, which is reflected and radiated by the heat-reflecting layer of the composite element. Such heating panels will be used as part of a wall of a living room or an office.
In this state of the art, the incorporation of the semiconducting layer into the laminate can take place in that finely comminuted carbonaceous pyropolymer, in the form of small particles or as powder, is mixed with a suitable support or vehicle in such a way that it is applied, spread or otherwise brought to the surface of a resin-coated glass cloth, paper, felt, cardboard, etc., as the laminated substrate or on a wood veneer, which is used in the laminated panel. The finely comminuted carbonaceous pyropolymer can also be mixed with the resin or polymer material, with which a specially reinforcing base material is to be impregnated or which is to be applied on this base material as a coating, wherein this base material is applied in or on the substrate by immersion or coating, and the resulting coated substrate is subjected to a semi-hardening of the type that the semiconductive pyropolymer leads to a uniform impregnation and coating via the resulting semicured, laminated sheet.
DE 33 16 182 A1 discusses the use of molded articles, such as films, plates, or spatially molded structures, from the class of the pyrrole polymers, which are complexed with anions, as electrical heating elements, in particular, for the heating of corrosive liquids or gases. The molded articles can also be coated with organic plastics.
A polymeric composite heating element is described in DE 35 24 631 A1 and has the form of a film, tube, or rod. Such polymeric composite heating elements can be used as such as heating sources, or can be laminated with conventional plastic films in order to improve the material strength.
The use and production of electrically conductive thermoplastic polyurethanes are known from DE 33 21 516 A1. Corresponding products are suitable for, among other things, the production of 1- to 2-mm-thick films for surface heating elements.
Thus, heating devices with electrically conductive plastic are rudimentarily known, but the entire state of the art does not contain any data or suggestion concerning how such heating devices are to be equipped and produced so that they can be used in actual practice.
Therefore, the problem of the present invention concerns the design of a heating device with an electrically conductive plastic and the corresponding object with the least possible expense.